What is the 1.49 fee on Coinbase?

Could you please explain what the 1.49 fee on Coinbase actually represents? I've noticed this fee on several transactions and I'm a bit puzzled as to its purpose and how it's calculated. Is it a fixed fee or does it vary based on the transaction amount? Also, is this fee exclusive to Coinbase or do other cryptocurrency exchanges charge similar fees? I'm trying to understand the costs involved in trading cryptocurrencies and would appreciate your clarification on this matter.